Anti-locking brake system

Abstract

An anti-locking brake system for traction control and vehicle dynamics control such that a pump for actuating a wheel brake removes brake fluid from a brake pressure generating unit and supplies it to the wheel brake. Disposed between the brake pressure generating unit and an input connection of the pump is a valve arrangement in the form of a 2-connection/3-position valve, which in a non-actuated (normal) position blocks the connection between the brake pressure generating unit and the input connection of the pump. In a first actuating position the valve arrangement establishes a secondary flow connection between the brake pressure generating unit and the input connection of the pump, and in a second actuating position establishes a primary flow connection between the brake pressure generating unit and the input connection of the pump. The primary flow connection has a larger flow cross section than the secondary flow connection.

What is claimed is:  
     
       1. Anti-locking brake system, which is set up in particular for traction control and vehicle dynamics control having 
       a pump for actuating a wheel brake, which pump removes brake fluid from a brake pressure generating unit and supplies it to the wheel brake, and  
       a valve arrangement which is disposed between the brake pressure generating unit and an input connection of the pump and takes the form of a two-connection/three-position valve, said valve arrangement including:  
       a first valve element, which is biased into a normal position by a first spring arrangement, said first valve element being supported via the first spring arrangement against a housing;  
       a first actuating device for bringing said first valve element into a first actuating position;  
       a further valve element which is biased into a normal position thereof by a further spring arrangement, said further spring arrangement is supported via the first valve element wherein the further spring arrangement lies against a supporting part, said supporting part lying between the first valve element and the first spring arrangement; and  
       a further actuating device for bringing the further valve element into a second actuating position;  
       said valve arrangement, in a non-actuated normal position blocks the connection between the brake pressure generating unit and the input connection of the pump, and  
       in a first actuating position establishes a secondary flow connection between the brake pressure generating unit and the input connection of the pump; and  
       in a second actuating position establishes a primary flow connection between the brake pressure generating unit and the input connection of the pump, wherein the primary flow connection has a larger flow cross-section than the secondary flow connection and  
       upon each actuation of the valve arrangement the arrangement initially moves into the first actuating position and then the second actuating position; and is then, through adjustment of the actuating force, selectively adjustable either into the first actuating position or into the second actuating position.  
     
     
       2. An anti-locking brake system for traction control and vehicle dynamics control comprising: 
       a pump for actuating a wheel brake, said pump removes brake fluid from a brake pressure generating unit and supplies it to the wheel brake;  
       a valve arrangement disposed between the brake pressure generating unit and an input connection of the pump,  
       said valve arrangement comprises a two-connection/three-position valve including:  
       a first valve element, which is biased into a normal position by a first spring arrangement, said first valve element being supported via the first spring arrangement against a housing;  
       a first actuating device for bringing the first valve element into a first actuating position;  
       a further valve element biased into a normal position thereof by a further spring arrangement, said further spring arrangement being supported via the first valve element, wherein the further spring arrangement lies against a supporting part, said supporting part lying between the first valve element and the first spring arrangement; and  
       a further actuating device for bringing the further valve element into a second actuating position;  
       wherein the valve blocks the connection between the brake pressure generating unit and the input connection of the pump in a non-actuated normal position;  
       said valve arrangement establishes a secondary flow connection between the brake pressure generating unit and the input connection of the pump in a first actuating position;  
       said valve arrangement establishes a primary flow connection between the brake pressure generating unit and the input connection of the pump in a second actuating position wherein the primary flow connection has a larger flow cross-section than the secondary flow connection; and  
       said valve arrangement, upon each actuation, initially establishes the secondary flow connection and then establishes the primary flow connection, wherein during further actuation of the valve arrangement the valve arrangement is, through adjustment of the actuating force, selectively adjustable either into the primary or into the secondary flow connection.  
     
     
       3. The anti-locking brake system defined in  claim 2  wherein one or both of the first actuating device and the further actuating device are controlled by one or both of electromagnetic and hydraulic means. 
     
     
       4. The anti-locking brake system defined in  claim 2  wherein the first valve element and the further valve element are actuated by a common actuating device. 
     
     
       5. The anti-locking brake system defined in  claim 3  wherein the first valve element is dome shaped and the further valve element is spherical, wherein the further valve element is disposed inside the first valve element. 
     
     
       6. The anti-locking brake system defined in  claim 4  wherein the first valve element is dome shaped and the further valve element is spherical, wherein the further valve element is disposed inside the first valve element. 
     
     
       7. The anti-locking brake system defined in  claim 5  wherein the bias force of the first spring arrangement is greater than the bias force of the further spring arrangement. 
     
     
       8. The anti-locking brake system defined in  claim 6  wherein the bias force of the first spring arrangement is greater than the bias force of the further spring arrangement. 
     
     
       9. The anti-locking brake system defined in  claim 7  wherein the primary flow connection is further defined by a first sealing seat formed on the housing of the valve arrangement and by the first valve element. 
     
     
       10. The anti-locking brake system defined in  claim 8  wherein the primary flow connection is further defined by a first sealing seat formed on the housing of the valve arrangement and by the first valve element. 
     
     
       11. The anti-locking brake system defined in  claim 9  wherein the secondary flow connection is further defined by a second sealing seat formed on the first valve element and by the further valve element. 
     
     
       12. The anti-locking brake system defined in  claim 10  wherein the secondary flow connection is further defined by a second sealing seat formed on the first valve element and by the further valve element. 
     
     
       13. The anti-locking brake system defined in  claim 11  wherein the first spring arrangement is supported against the housing of the valve arrangement. 
     
     
       14. The anti-locking brake system defined in  claim 12  wherein the first spring arrangement is supported against the housing of the valve arrangement. 
     
     
       15. The anti-locking brake system defined in  claim 13  wherein the further spring arrangement is supported via the first valve element. 
     
     
       16. The anti-locking brake system defined in  claim 14  wherein the further spring arrangement is supported via the first valve element. 
     
     
       17. The anti-locking brake system defined in  claim 4  wherein the further valve element is integrally connected to the common actuating device. 
     
     
       18. The anti-locking brake system defined in  claim 17  wherein the further spring arrangement biases the actuating device so that the further valve element occupies a normal position, wherein the further spring arrangement is supported against the housing of the valve arrangement. 
     
     
       19. The anti-locking brake system defined in  claim 2  wherein the supporting part further includes fluid passages and is frictionally connected to the valve element. 
     
     
       20. The anti-locking brake system defined in  claim 19  wherein the frictional connection between the supporting part and the valve element is by means of an interference fit.